1. What is extraterritorial evidence? Extraterritorial evidence refers to evidence formed outside the territory of the People’s Republic of China and the People’s Republic of China. This evidence must be certified by the notary authority of the country where it is located and certified by the People’s Republic of China and the People’s Republic of China. The country's embassy or consulate in the country shall authenticate it, or perform the certification procedures stipulated in the relevant treaties between the People's Republic of China and the country where it is located. The evidence provided by the parties to the Patent Reexamination Board was formed in China, Macau, and Taiwan, and relevant certification procedures must be completed. 2. What matters should be paid attention to in the certification procedures of foreign evidence. However, in the following three situations, for the above two types of evidence, the parties may not go through the relevant certification procedures in the invalidation procedure: (1) The evidence can be obtained from other countries, Macao, and Taiwan Obtained from domestic public channels outside the region, such as foreign patent documents obtained from the Patent Office, or foreign literature obtained from public libraries; (2) There is other evidence sufficient to prove the authenticity of the evidence; (3) The other party recognizes the authenticity of the evidence.